Clinical Scorecard: Techniques for Microsurgical Access to the Carotid Dural Rings: A Step-by-Step Guide

At a Glance

Key Highlights

• The carotid dural rings consist of proximal and distal fibrous layers anchoring the clinoid segment of the ICA at the skull base.
• A stepwise microsurgical approach, including anterior clinoidectomy and careful dural incisions, is essential to avoid injury to the ICA, optic nerve, and oculomotor nerve.
• Hemostasis of the cavernous sinus can be managed with fibrin glue or saline-soaked hemostatic sponges without compromising neurovascular structures.

Guideline-Based Recommendations

Diagnosis

• Identify the anatomical landmarks including the distal dural ring, carotid cave, and optic strut via microsurgical exposure.
• Confirm the position of the ophthalmic artery and aneurysm neck intraoperatively.

Management

• Position the patient prone with the head turned 30° opposite the approach and fixed in a Mayfield clamp with vertex down.
• Perform a frontotemporal craniotomy via conventional pterional or sphenoid ridge keyhole approach.
• Conduct anterior clinoidectomy by drilling the greater sphenoid wing, coagulating and incising the meningo-orbital band, peeling dura propria, and removing the anterior clinoid process.
• Drill the optic strut under continuous irrigation to expose the carotid dural rings and proximal ICA.
• Incise the dura along the falciform ligament and optic sheath carefully to expose and mobilize the ICA and aneurysm neck.
• Apply fibrin glue or hemostatic sponges for cavernous sinus bleeding control.

Monitoring & Follow-up

• Intraoperative visualization of the ophthalmic artery patency and integrity of surrounding neurovascular structures.
• Continuous microscopic magnification to avoid injury to the ICA, optic nerve, and oculomotor nerve.

Risks

• Iatrogenic injury to the internal carotid artery due to lack of adventitial layer in the clinoid segment.
• Optic nerve damage from dural or bony manipulation.
• Oculomotor nerve injury during dural peeling or anterior clinoidectomy.
• Cerebrospinal fluid leaks from dural breaches.
• Aneurysm rupture during dissection.

Patient & Prescribing Data

Patients undergoing microsurgical skull base procedures involving the paraclinoid region and carotid dural rings

Meticulous microsurgical technique with stepwise exposure and careful hemostasis is critical to optimize outcomes and minimize complications.

Clinical Best Practices

• Use microscopic magnification throughout the procedure for precise dissection.
• Preserve the frontal branch of the facial nerve during skin and muscle dissection.
• Maintain continuous irrigation during drilling to prevent thermal injury.
• Peel the dura propria carefully to expose the anterior clinoid process without damaging the cavernous sinus contents.
• Control cavernous sinus bleeding with fibrin glue or gentle pressure using hemostatic sponges.
• Confirm vascular anatomy and aneurysm neck exposure before clipping.

References

• Kobayashi et al., 1989 - Description of carotid cave
• Yaşargil - Frontotemporal skin incision technique
• Anatomical and surgical considerations of carotid dural rings